Abstract We propose to develop a social computing technology called the Diabetes Networking Tool (DNT), that enhances Type II Diabetes and pre-diabetes patients? ability to self-manage and avoid disease complications by bolstering family, household, and community-based support mechanisms. Type II Diabetes Mellitus is a life-long condition that is a serious and growing public health problem, and that requires constant self-management by the patient to avoid dangerous complications. Prior research by the research team and others indicates that a Type II diabetes patient?s social network can help a patient improve self-management and developed a demonstration smart-phone app around this concept. Family and community relationships influence an individual?s ability to make successful diabetes-related behavior change, and thus the success of self-management. These relationships can provide positive reinforcement and personal encouragement for key activities such as adherence to medication and blood-testing schedules and getting exercise. This proposal seeks to expand the prior research and translate it into a commercial-grade DNT product that will leverage these family and community resources through a fully-developed smartphone app. DNT allows a patient to create a private local social network of household/family/friends that can support the patient with her/his diabetes self-management behaviors, such as adhering to medication and glucose-testing schedules, finding people to exercise with, and sharing of information such as food shopping tips and positive social reinforcement. DNT also gives the patient access to local community resources, uses geo-fencing technology, and allows location specific information (e.g., healthy grocery sales, health fairs) to be posted and shared. Gaming features to be developed, such as earning badges and participating in social challenges, can increase engagement and frequency of use. Our team brings a unique combination of leaders and experts in user-centered and social computing and behavioral science research. Phase I Aims are to: 1. Define needs and opportunities for DNT social support using participatory design methods within a sample of diverse middle and low-income communities. 2. Design the DNT user interface and develop a complete DNT app prototype. 3. Conduct initial formative assessment of the prototype DNT for usability and perceived usefulness. The full DNT product can improve diabetes-related self-management, as well as increase scientific understanding of how an augmented social support system can benefit diabetes management and potentially reduce disease complications.